John Gill Commentary 1 Kings 14:15

"For Jehovah will smite Israel, as a reed is shaken in the water; and he will root up Israel out of this good land which he gave to their fathers, and will scatter them beyond the River, because they have made their Asherim, provoking Jehovah to anger." — 1 Kings 14:15 (ASV)

And the Lord shall smite Israel as a reed is shaken in the
water
Either by the wind or by the stream; and may signify the fluctuating and uncertain condition Israel should be in future reigns, through civil wars, and the translation of the kingdom into different families; so that there was continually disquietude and uneasiness, and no settled peace and tranquillity:

and he shall root up Israel out this good land he gave to their
fathers ;
which was brought about, first by Tiglathpileser, and then by Shalmaneser, kings of Assyria, that carried them captives from hence:

and shall scatter them beyond the river ;
the river Euphrates, as the Targum: or, as others, the river Gozan, (2 Kings 17:6)

because they have made their groves, provoking the Lord to anger :
in which groves they placed idols, and worshipped them, which was highly provoking to the Lord, and the cause of their dispersion.